Re: New approach to generating charts in PSPP ?

[Ben Pfaff]

On Wed, Aug 02, 2017 at 07:45:17PM +0200, John Darrington wrote:
> A number of users have been commenting for a while that PSPP's
> charts are somewhat clunky.
> 
> Because of this, I've been looking for a while for graphing libraries
> to help us.  There is of course gnuplot (which despite its name is not
> GNU software), but that has some practical and some licensing issues.
> Amoung others that I found is GseGrafix (which IS a GNU program).
> This certainly doesn't have any licensing problems (it's GPLv3+). But
> 1. It needs gnome canvas which does not typically get installed on
> modern GNU/Linux distros, and is incompatible with Gtk+3 anyway; and
> 2. It's not a library.
> 
> So I've forked it and replaced gnomeCanvas with cairo, and massaged it
> a little to provide a callable API.  I've registered a project at
> http://sv.gnu.org/p/gsegrafix-experimental and hacked the PSPP code to
> use this library.
> 
> I'm attaching results of a simple graph with both the new an the old.
> 
> What do people think about replacing our existing charting code with
> GseGrafix?
> 
> The advantages that I can see are:
> 
>  1. Less code in PSPP.
> 
>  2. Clean separation of the charting code.
> 
>  3. Better (in my opinion) graphics.
> 
>  4. 3D plots can be generated.
> 
>  5. If we can persuade GseGrafix upstream to accept our changes, then
>     somebody else maintains it for us.
> 
> On the down side:
> 
>  1. GseGrafix currently lacks some types of chart (eg: BoxPlots,
>      Piecharts)
> 
>  2. It's another library that users have to install.

The results look nicer than what we have.

Does geografix provide any provisions for interactive editing?  That is
a feature that I imagine our users would really appreciate.